RE: I2C interrupt while softdevice enabled

Krzysztof Chruscinski — Mon, 17 Nov 2014 14:24:37 GMT

If NRF_TWI1->INTENSET=... is removed then you have disabled peripheral interrupt and it will never go to nvic. There are two stages of interrupt control: in the peripheral using INTENSET/INTENCLR you enable particular peripheral events as interrupts and then in NVIC you control general interrupt from this peripheral.

It is recommended to access nvic using softdevice API. As TWI is not used by softdevice you can access TWI registers directly.

As mnhs mentioned, it is vital to set proper interrupt priority (1 or 3, you can also use app_irq_priority_t from app_util_platform.h in SDK)

RE: I2C interrupt while softdevice enabled

mnhs — Sat, 15 Nov 2014 15:41:08 GMT

Try to use sd_nvic_enableIRQ(SPI1_TWI1_IRQn); instead of "non-sd" NVIC_EnableIRQ(). By default all the interrupt priorities are set to 0 (highest priority) which is reserved exclusively for SoftDevice. Thus, the SoftDevice may become unstable. Alternatively, you can try to set the priority of SPI1_TWI1_IRQn interrupt to 1 - 3.

I am also not sure if you can put the sd_app_evt_wait directly into interrupts. It should be in the main cycle. When the handler ends it job, it jumps back to the main cycle and goes to sd_app_evt_wait.